BMR vs. TDEE: Estimating Calories for Weight Loss
Your resting energy estimate is not your daily eating target. BMR describes energy use under strictly controlled resting conditions. TDEE covers the whole day, including food processing and physical activity. Understanding the distinction helps you use a calorie calculator without treating an estimate as a personal prescription.[1][2]
BMR, RMR, TDEE and EER: four useful terms
| Term | Meaning |
|---|---|
| BMR: basal metabolic rate | Energy expenditure under strict basal conditions, including fasting and complete rest. |
| RMR / REE: resting metabolic rate / resting energy expenditure | Energy used while awake and resting; measurement conditions differ from BMR. |
| TDEE: total daily energy expenditure | Resting energy, the thermic effect of food, and physical activity combined. |
| EER: estimated energy requirement | A prediction of daily energy needs; linked to TDEE in weight-stable adults. |
These labels are sometimes used loosely online. The Mifflin–St Jeor equation estimates resting energy expenditure; it does not measure BMR. Check the method behind the number, particularly when comparing two apps.[1][3]
TDEE includes more than workouts
Daily energy use includes maintaining normal body functions, processing food and moving. Activity includes exercise and everyday movements such as commuting, housework and walking between tasks. Korean public-health guidance also describes these three broad components.[4]
A workout schedule alone does not describe your whole day. Someone who sits for most working hours has a different activity pattern from someone who spends much of the day moving. There is no fixed percentage split that accurately represents everyone.[1]
BMR, RMR and TDEE describe different concepts.
BMR
Basal energy expenditure measured under strict fasting and resting conditions.
RMR
Resting energy expenditure. A calculator estimates it; it does not measure it.
TDEE
The whole day: resting energy + food processing + daily activity and exercise.
BMR or RMR alone is not a daily eating target.
Sources: Mifflin et al. (1990); NASEM (2023); KDCA · General information, not an individual prescription.
How the Life Choice Note calculator estimates calories
Our BMR and TDEE calculator uses two separate approaches: Mifflin–St Jeor for resting energy, and the 2023 National Academies EER equations for adults aged 19+ for daily maintenance needs. The second result is not produced simply by multiplying the first by an activity factor.
The original Mifflin–St Jeor study developed its prediction from healthy adults whose resting expenditure was measured using indirect calorimetry. The equation uses weight, height, age and the study’s sex categories. It remains a prediction for an individual.[3]
The National Academies equations were developed within the US and Canadian dietary reference framework. They use activity-specific equations and are not individually calibrated measurements, including for Korean readers.[5]
A worked example: 35 years, 165cm and 70kg
Consider a fictional, weight-stable adult woman who is not pregnant or breastfeeding. Her height is about 5ft 5in and weight about 154lb. Using the female Mifflin–St Jeor equation:
10 × 70 + 6.25 × 165 − 5 × 35 − 161 = 1,395.25kcal/day.[3]
| Estimate | Method or assumption | Rounded result |
|---|---|---|
| Resting energy | Mifflin–St Jeor | 1,395kcal/day |
| Daily maintenance needs | NASEM 2023: inactive | 2,103kcal/day |
| Daily maintenance needs | NASEM 2023: low active | 2,269kcal/day |
The last two rows change the assumed activity category. They do not establish which category this fictional person belongs in. Extra decimal places would not make the prediction more precise for her.[5]
Do not add the resting and maintenance figures together. Maintenance needs already include resting expenditure. Subtracting them does not reveal “workout calories” either: they are independent estimates, and total expenditure also includes food processing and nonexercise activity.[1][5]
Fictional example: woman aged 35 · 165 cm · 70 kg
Resting estimate: RMR
About 1,395 kcal/day
Mifflin–St Jeor equation
Whole-day estimate: EER
NASEM 2023 equation
Inactive: about 2,103 kcal/day
Low active: about 2,269 kcal/day
Independent equation outputs: do not add or subtract them.
Not personal eating targets.
Fictional, weight-stable adult who is not pregnant or breastfeeding. Rounded values.
Sources: Mifflin et al. (1990); NASEM Energy DRI (2023) · General information, not an individual prescription.
Turn the estimate into a useful starting point
- Check inputs and units. Use current measurements and distinguish kilograms from pounds, and centimetres from inches.
- Describe an ordinary week. Include work, commuting and home activity alongside exercise.
- Separate maintenance from weight loss. An EER result is not an automatic calorie-deficit prescription. Health and nutritional needs still matter.[2][5]
- Compare estimates with your records. Review portions, drinks and activity alongside weight trends rather than responding to one isolated reading.[6]
Energy needs can change during weight loss. NIDDK explains why a constant calorie reduction does not produce the same amount of weight loss indefinitely. Revisit the assumptions instead of treating the starting estimate as a permanent rule.[6]
Exercise sessions alone do not define your activity level.
Commute
Mostly sitting, or do you walk or cycle?
Work
Mostly seated, standing, or moving around?
Daily movement
Include housework, shopping and walking.
Exercise
Check actual frequency, duration and intensity.
If activity is already included, do not add exercise calories again.
Sources: NASEM (2023); KDCA obesity information · General information, not an individual prescription.
Is the number on a body-composition report measured?
A device displaying “BMR” may be reporting an equation-based estimate. InBody, for example, describes calculating this value from lean body mass. Check your device documentation.[9] Resting-energy assessment using indirect calorimetry measures oxygen consumption and carbon dioxide production; a figure on a scale’s body-composition report should not automatically be treated as that test.[1]
When generic calorie calculations are unsuitable
Children, teenagers, and people who are pregnant or breastfeeding require an approach appropriate to their life stage. NIDDK’s Body Weight Planner specifically excludes people under 18 and those who are pregnant or breastfeeding.[7]
Seek individual advice when illness, medication or eating-disorder concerns affect dietary planning. NICE treats low-energy and very-low-energy diets as supported clinical interventions for selected people, with nutritional completeness and follow-up—not a routine do-it-yourself response to a calculator result.[8]
Frequently asked questions
Is BMR a universal minimum calorie intake?
No single BMR estimate establishes a safe intake. Nutritional adequacy, duration, health and clinical context matter. Eating above that number does not automatically make a diet adequate either.[2][8]
Should I add exercise calories to TDEE?
First check what activity the estimate already includes. Adding the same workout again would count it twice.[1]
Why am I not losing weight as predicted?
Inputs, activity assumptions, food records and changing energy needs can all affect the comparison. Review these before repeatedly lowering intake; professional support can help interpret the pattern.[6]
Try the tool: Compare your resting-energy and daily-needs estimates.
Sources
Checked 1 October 2026. The worked example is educational and is not a personalised recommendation.
- NASEM. Dietary Reference Intakes for Energy (2023), Chapter 4, Table 4-1.
- FAO/WHO/UNU. Human energy requirements: Principles and definitions.
- Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals. 1990.
- KDCA. Healthy eating for weight management (Korean).
- NASEM. Dietary Reference Intakes for Energy (2023), Summary, Table S-3.
- NIDDK. NIH Body Weight Planner: researcher explanation.
- NIDDK. Body Weight Planner.
- NICE NG246. Physical activity and diet.
- InBody USA. How is BMR measured? Manufacturer documentation of its calculation method, not a product endorsement.
General health information from Life Choice Note; not a substitute for individual medical assessment or treatment.
